Raja has Published 760 Articles

How can we convert a JSON array to a list using Jackson in Java?

raja

raja

Updated on 06-Jul-2020 12:30:14

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A Jackson is a Java-based library and it can be useful to convert Java objects to JSON and JSON to Java Object. A Jackson API is faster than other API, needs less memory area and is good for the large objects. We can convert a JSON array to a list using the ... Read More

How can we serialize a list of objects using flexjson in Java?

raja

raja

Updated on 06-Jul-2020 12:26:47

1K+ Views

The Flexjson is a lightweight library for serializing and deserializing Java objects into and from JSON format. We can serialize a list of objects using the serialize() method of JSONSerializer class. This method can perform a shallow serialization of the target instance. We need to pass a list of objects of List type as an argument to the serialize() method.Syntaxpublic String serialize(Object ... Read More

How to create a JSON using Jackson Tree Model in Java?

raja

raja

Updated on 06-Jul-2020 12:20:51

960 Views

In the Jackson library, we can use the Tree Model to represent the JSON structure and perform the CRUD operations via JsonNode. This Jackson Tree Model is useful, especially in cases where a JSON structure does not map to Java classes. We can create a JSON in the Jackson library using the JsonNodeFactory, it ... Read More

How can we create a JSON using JsonGenerator in Java?

raja

raja

Updated on 06-Jul-2020 12:19:03

5K+ Views

The JsonGenerator is a base class that defines public API for writing JSON content. The instances are created using factory methods of a JsonFactory instance. Once we can get the JsonGenerator from factory instance then use the writeStartObject() for writing starting marker of a JSON Object value,  writeFieldName() method for writing a field name, writeString() ... Read More

When can we call @JsonAnyGetter and @JsonAnySetter annotations in Java?

raja

raja

Updated on 06-Jul-2020 12:14:04

1K+ Views

The @JsonAnyGetter annotation enables to use a Map as a container for properties that we want to serialize to JSON and @JsonAnySetter annotation instructs Jackson to call the same setter method for all unrecognized fields in the JSON object, which means that all fields that are not already mapped to a property or setter ... Read More

How can we ignore the fields during JSON serialization in Java?

raja

raja

Updated on 06-Jul-2020 12:06:01

12K+ Views

If there are fields in Java objects that do not wish to be serialized, we can use the @JsonIgnore annotation in the Jackson library. The @JsonIgnore can be used at the field level, for ignoring fields during the serialization and deserialization.Syntaxpublic @interface JsonIgnoreExampleimport java.io.*; import java.util.*; import com.fasterxml.jackson.core.*; import com.fasterxml.jackson.databind.*; import com.fasterxml.jackson.annotation.*; ... Read More

How to serialize the order of properties using the Jackson library in Java?

raja

raja

Updated on 06-Jul-2020 12:01:48

3K+ Views

The @JsonPropertyOrder is an annotation to be used at the class-level. It takes as property a list of fields that defines the order in which fields can appear in the string resulting from the object JSON serialization. The properties included in the annotation declaration can be serialized first(in defined order), followed by ... Read More

How to implement a custom serializer using the Jackson library in Java?

raja

raja

Updated on 06-Jul-2020 11:52:25

936 Views

The Jackson API provides a number of methods to work with JSON data. By using Jackson API, we can convert Java objects to JSON string and reform the object from the JSON string. We can implement a custom serializer using the StdSerializer class and need to override the serialize(T value, JsonGenerator gen, SerializerProvider ... Read More

Convert CSV to JSON using the Jackson library in Java?

raja

raja

Updated on 06-Jul-2020 11:44:03

7K+ Views

A Jackson is a Java JSON API that provides several different ways to work with JSON. We can convert CSV data to JSON data using the CsvMapper class, it is specialized ObjectMapper, with extended functionality to produce CsvSchema instances out of POJOs. We can use the reader() method for constructing ObjectReader with default settings. In order ... Read More

How to deserialize a JSON array to list generic type in Java?

raja

raja

Updated on 06-Jul-2020 11:38:01

1K+ Views

The Gson library provides a class called com.google.gson.reflect.TypeToken to store generic types by creating a Gson TypeToken class and pass the class type. Using this type, Gson can able to know the class passed in the generic class.Syntaxpublic class TypeToken extends ObjectWe can deserialize a JSON array to a generic type of list in ... Read More

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